Can animal waste be harnessed to promote development?

Using bio-gas to produce energy can reduce GHG emissions and increase agricultural productivity. But it also can vastly improve the quality of life for people living in poor, rural communities by providing them with electricity and cooking fuel, saving them from having to walk long distances to collect firewood.

A neighbor from Mejillones community checking a biogas pipeline. Image: HAV

The Mendez family lives in the Mejillones community just outside the city of Cobija in Pando, Bolivia. To support his family, Freddy works at two dairy farms. Roxana takes care of their two children, 13-year-old Prince and Kevin, age 5.

When Freddy is not home, young Prince is responsible for the herd of cows. Roxana spends most of her day doing the house chores, where cooking for her family is a time-consuming activity. Even though she has a gas stove that runs on liquefied petroleum gas (LPG), she has not used it in a long time.

Her LPG tanks have been stolen several times and purchasing them in the city involves extra cost and time. As a result, Roxana collects wood and cooks all daily meals for her family on a wood stove.Located in the Amazon rainforest, Pando is one most isolated and poorest departments in Bolivia: it is not connected to the national electricity or natural gas grids. Half of the population lives in rural areas and the majority do not have access to electricity.

Like Roxana, they spend hours each day walking long distances to collect wood for their cook stoves, which increases deforestation and exposes families to harmful emissions.

Méndez family. Image: HAV

Residents in urbanized areas of Pando rely on subsidized and expensive diesel-based electricity that is a major source of greenhouse gas (GHG) emissions.

The lack of sustainable energy in both urban and rural Pando creates barriers to business, schoolingand the general well-being of those in most need. Adopting innovative approaches to provide sustainable energy for all is urgent. So what’s the solution?

Producing renewable energy using locally available resources is a promising solution for Pando and similar areas around the world. Anaerobic digestion (AD) is a waste-to-energy technology that captures biogas-containing methane (CH4) from the degradation of organic wastes by bacteria that live in the absence of oxygen.

Biogas can be burned directly for cooking and heating or used in a generator to produce electricity. Manure is the preferred feedstock for AD as it contains the methane-producing bacteria and it is readily available in farms with animal operations.

The effluent from the digester retains the nutrients from the manure and can be used as organic fertilizer. Besides producing energy, AD systems have proven to reduce GHG emissions (up to 50%), reduce feedstock odors, and facilitate waste handling.

After conducting research on renewable energy and AD systems in the U.S., I looked for opportunities to develop the AD sector in my home country of Bolivia. In December 2014, Dr. Rebecca Larson and I, both of us from the University of Wisconsin-Madison, made our first trip to Pando and started a fruitful collaboration with the Universidad Amazónica de Pando (UAP).

Installing a bio-gas tank. Image: HAV

We installed a first digester in the UAP campus as an experimental station to understand how the system responded to local conditions.

The design is simple and the system was built with local materials and the support of UAP students, who were trained in system operations and troubleshooting, to guarantee its replicability in the future.

After troubleshooting and finalizing the design, data was collected for a period of over five months to evaluate the technical feasibility of the project.

In December of 2015 we made our second trip to Pando. We installed a second digester in the Mendez family’s home with the help of UAP students and active participation of all family members. The system doubles the size of the first one and will provide more than enough biogas for their cooking requirements.

Roxana was happy to see our daily progress during installation, knowing that it would significantly reduce the time she devotes to collecting firewood and, most importantly, would benefit her family’s health.

Moving forward, we envision the installation of AD systems that will provide biogas for cooking and electricity generation for isolated families throughout Pando, which would nicely complement the current government strategy of providing all Bolivians with electricity by 2025.

For this, we are currently evaluating the potential of producing electricity with a small generator at the first experimental digester site. Local community leaders have already visited the digester sites and have expressed their interest in using this technology for existing dairy and swine projects. Our work has also centered on local capacity-building, having trained students from the UAP on these methods so that they can lead the implementation and expansion of these systems.

Projects like this one have a clear potential to expand across the Amazon region of Bolivia (which covers 60% of the country) and other areas around the world. AD systems not only can contribute to climate change mitigation by significantly reducing GHG emissions, but the effluent of the digester used as organic fertilizer can help increase agricultural productivity, thereby helping communities to better cope with a changing climate that affects their food security.

Roxana and Kevin, her son. Image: HAV

Beyond the environmental benefits, AD systems provide lower-cost energy, which has tremendous potential for boosting development and reducing poverty in isolated areas.

For this to happen, more funding will be needed to develop additional testing systems within the communities, evaluate their performance, and train local people to take ownership of these innovative initiatives.

Horacio Aguirre-Villegas is a research associate at the University of Wisconsin-Madison. He holds a graduate degree in Industrial Engineering from Universidad Católica Boliviana, a Masters in Industrial Management from IQS School of Engineering and a Ph.D. in Biological Systems Engineeringfrom the University of Wisconsin-Madison. His email is aguirreville@wisc.edu